Recently, along with the rapid development of the technology, mobile products having a biometric identification function have been gradually used in our daily lives. Fingerprint technology has attracted more and more attentions due to the uniqueness of fingerprint. Push-type and swipe-type fingerprint identification techniques manufactured using a silicon-based process have been integrated into the mobile products, and in future, the focus is on the fingerprint identification technique at a display region.
In a fingerprint current identification circuit in the related art, each fingerprint sensor consists of one photosensitive diode and one switching transistor. In the case of scanning the fingerprint, light beams from a light source may be reflected by valleys and ridges of the fingerprint in different ways, so an intensity of the light beams received by the photosensitive diode may change, resulting in different photocurrents. Under the control of the switching transistor, the photocurrents flowing through the photosensitive diodes may be read, so as to detect the valleys and ridges of the fingerprint. However, for a conventional fingerprint photocurrent detection method, the fingerprint photocurrent is directly detected, so an intensity of a signal is relatively low and a noise may easily interfere with the signal.